set combobox value javafx dynamicaly - javafx

Question

i hava probleme to fil a combobox ,
i create buttons dynamicaly where i set a event , whre i use a methode (from where i creat my list ) where i change the view , and set a combobox ,
createButton
private Button createButton(String text) {
Button button = new Button(text);
button.setMaxSize(Double.MAX_VALUE, Double.MAX_VALUE);
button.setPrefSize(100, 100);
button.setOnAction(e -> {
try {
getImprByProduct(text);
} catch (IOException ex) {
Logger.getLogger(DuplicataController.class.getName()).log(Level.SEVERE, null, ex);
}
});
button.setId("btn");
System.out.println("************************** fin creation bouton");
return button;
}
getImprByProduct give me a list of my product wich i want to set in the combobox ,
public List<String> getImprByProduct(String prd) throws IOException {
//afficher Viewdupcontroller
ViewDupController dupController = new ViewDupController();
FXMLLoader fXMLLoader = new FXMLLoader();
fXMLLoader.load(getClass().getResource("/view/application/duplicata/ViewDuplicata.fxml").openStream());
if ((startPage1.global_Session.isOpen()) || (startPage1.global_Session.isConnected())) {
startPage1.global_Session.close();
}
startPage1.global_Session = HibernateUtil.getSessionFactory().openSession();
startPage1.global_Session.beginTransaction();
List<Impression> listImpr = impressionUse.getListImpression_SS();
for (Impression i : listImpr) {
Voucher v = new VoucherUse().getVoucherById(startPage1.global_Session, i.getIdVoucherDebutFk());
if (v.getProduit().getDesignation().equals(prd)) {
result.add(i);
}
}
startPage1.global_Session.getTransaction().commit();
startPage1.global_Session.close();
int p = 0;
for (Impression i : result) {
System.out.println("list des ID impression : " + i.getIdImpression());
list.add(i.getIdImpression().toString());
p++;
}
ListIterator li = list.listIterator();
while(li.hasNext()){
System.out.println("contenu list : " + li.next());
}
System.out.println("*********************************avant add fxml getroot affichage");
anch.getChildren().clear()
anch.getChildren().add(fXMLLoader.getRoot());
dupController.com(list); // i where i call the the methode in the controller of the new view ( of combobox )
return list;
}
dupController.com(list);
ObservableList obList = FXCollections.observableList(list);
combo1.getItems().clear();//where error is
combo1.setItems(obList);